Smell

I have mentioned that G likes to smell me?

I decided to learn more about smell.  I've been slowly getting through Bonnie Blodgett's book Remembering Smell.  Fascinating!

Have you ever considered which of your senses you'd give up if you had to lose one?  Bonnie writes that most people, without thinking, would choose to give up their sense of smell.  Through an accident, Bonnie did lose her sense of smell, and she describes what a tremendous tragedy that is.  I had no idea how smell-dependent humans are.

Here are some interesting excerpts from the book:

"The long, thin olfactory bulb connects directly to the amygdala and the septum, which are parts of the limbic system, the structure that controls our most emotional and instinctive behaviors....  Unlike images and sounds, one pathway for odors goes directly to the brain's emotion and memory centers without being filtered by the circuits involved in higher intelligence."  (pg 26)

"Unlike smell, the other senses take a direct route to the high brain.  They don't pick up input from memory and emotion first, as smells do."  (pg 45)

Here Bonnie is quoting smell experts:
"The neurological interconnection between the sense of smell (olfaction) and emotion is uniquely intimate.  The areas of the brain that process smell and emotion are as intertwined and codependent as any two regions in the brain could possibly be." 
"[The sense of smell] is very sensitive, learns quickly, and forgets nothing, but it has no judgment about what ought to be remembered and what might be forgotten... It ensures the identification of odors vital to the individual's physical and psychological well-being." pg 69

What happened to Bonnie is that her accident damaged the inside of her nose... resulting in her brain concocting fake smells - horrible, foul smells - 24/7 for weeks.  After that, she totally lost all ability to smell.  She couldn't cook the simplest meal.  Once she almost burned down her house because she couldn't smell something burning.  She wrote that people who experience loss of smell typically gain weight because their bodies keep giving impulses to eat until they feel satiated (which, without smell, they never do).  How about that... feeling full doesn't come from having a full stomach!

In her book, Bonnie explores research on people who experience phantom pain (like the nonstop foul smells she endured).  She writes about a soldier who lost his right leg and began suffering pains that felt like electic shocks.  No treatments could stop the pain.  Finally the soldier participated in a study where he "viewed a mirror in which he saw a reflected image of his intact limb....  His pain was gone after just a few sessions.  Neuroscientists now know where his pains were coming from.  They were concocted from living memories and delivered via the nerve endings in the leg stump.  When the brain tried to move the absent limb, the result was an abnormal neural pattern experienced as searing pain.  But why are phantom feelings so nasty?  Is it because the senses - touch and smell, among others - are the first line of defense against the outside world?  The default response to a sense's absence is negative (sharp pains, foul smells) because no other logical explanation is available." pg 54

The soldier's brain had to be tricked into believing everything was ok before it would stop producing the pains.  Bonnie's brain also had to be tricked before it would stop producing the incessant foul smells.

There you have it.  I'm halfway through the book.  Don't ask why I felt it necessary to share all of this with you.  All I can say is that I think it's interesting.  Maybe you did too.